Polish Physicist Albert A. Michelson died #OTD in 1931
His most famous experiment - Michelson-Morley experiment, was conducted in 1887 in collaboration with Edward Morley. Their experiment for the expected motion of the Earth relative to the æther, the hypothetical medium in which light was supposed to travel, resulted in a null result. Their results leaded H. Lorentz to devise his Lorentz contraction equations as a means of explaining the null result.